JPH0453407B2 - - Google Patents

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a method of manufacturing an electrode plate for a color display device having an organic resin-dyed color filter used in a color liquid crystal display or the like. The present invention relates to a method of manufacturing an electrode plate in which a transparent electrode is formed on the top of the electrode plate.

<Prior Art> The conventional technology will be explained with reference to the schematic cross-sectional views of FIGS. 3 and 4.

FIG. 4 shows a conventional example of an electrode plate for a color display device, in which a transparent electrode 43 and a color filter 42 are laminated on a transparent substrate 41 with a thickness of about 1 mm. FIG. 3 shows another conventional example in which a color filter 32 is formed on a transparent substrate 31 and a transparent electrode 33 is formed thereon, in which the positions of the color filter and the transparent electrode are reversed from those in FIG. .

The transparent electrode is a transparent film of indium oxide to tin oxide, usually called ITO, with a thickness of about 200 to 300 Å, and the color filter is a relief image of a photosensitive resin patterned using a partial exposure method using a dye solution. Dyeing method (hereinafter referred to as relief dye method),
A method of dyeing with a dye liquid through a mask layer of a photosensitive resin with holes made only for the parts to be dyed by partial exposure on an easily dyeable resin layer (hereinafter referred to as mask dyeing method), and a printing method. The thickness formed by
It is a colored film of organic resin around 3μm. These electrode plates for color display devices are often used as one electrode plate of a liquid crystal display.

Plasma-assisted techniques such as ion plating and sputtering are used to form transparent electrodes on color filters.

<Problems to be solved by the invention> In the conventional example shown in FIG.
2 is laminated on the transparent electrode 43, for example, the effective voltage applied to the liquid crystal decreases by about 30%, resulting in a significant decrease in responsiveness and contrast. The example shown in FIG. 3 does not have this drawback because the transparent electrode 33 is on the color filter 32, but the conventional method of directly stacking the transparent electrode 33 on the color filter 32 has the drawback that the transparent electrode 33 and the color filter A sufficient adhesion force cannot be obtained between the transparent electrode and the transparent electrode, which may peel off during liquid crystal filling or during rubbing treatment.

For color filters formed using the relief dyeing method, the adhesion strength can be improved to some extent by placing an acrylic resin overcoat on the color filter, but this material can wrinkle and blister during heat treatment after the transparent electrode film is attached. It's easy to do.

After the transparent electrode film is attached, the transparent electrode is usually patterned by etching using a photoresist, but color filters formed by the relief dyeing method are prone to decolorization and cracks at this time.

Something happened.

<Means for Solving the Problems> The present invention involves reverse sputtering in an oxygen-containing atmosphere the color filter surface side of a transparent substrate having at least a color filter formed by coloring an organic resin layer with a colorant (dye, pigment). This is a manufacturing method of an electrode plate for a color display device, which is characterized by processing and forming a transparent electrode on the surface.Furthermore, on the reverse sputtering treated surface, there are cases where the surface is the color filter itself, and a case where a transparent electrode is formed on the surface. It may be the overcoat surface on the filter. Above all,
The material of the color filter or overcoat to be subjected to reverse sputtering is preferably gelatin, low molecular weight gelatin, peptide resin such as gris, casein, etc.

Here, reverse sparitzering will be explained. Positive sputtering uses the target, usually called the cathode, as the cathode, and ^the
An electric field of several tens to several thousand volts is applied in a vacuum of 10 ^-2 Torr to turn argon gas into plasma and bombard the target with argon ions. The impact knocks out the atoms or molecules of the target and forms a film of target components on the substrate (anode or ground) side.

Reverse sputtering is a method in which this polarity is reversed, and the substrate to be processed (color filter in this invention) is used as a cathode, and the surface of the substrate is bombarded with plasma of argon ions and oxygen gas.
Removes impurities and moisture from the color filter surface and oxidizes the surface slightly.

The introduction of oxygen gas in reverse sputtering is
This is done in the presence of an inert element such as argon. The ratio of oxygen gas ( _O2 ) to argon gas (Ar) is preferably in the range of 0.1 to 15%, preferably 0.4 to 3%. The pressure during sputtering is 10 ^-4 Torr ~
10 ^-2 Torr, the suitable voltage for the subverter is about 0.5 to 5 KV. Under these conditions, the treatment time becomes effective from about 10 seconds, and it is appropriate to set the upper limit to about 10 minutes.

<Effects> First, the cleaning action of reverse sputtering removes impurities and moisture from the surface, and the oxygen plasma oxidizes the surface of the color filter, creating a base that provides strong adhesion to metal oxide films such as ITO. There is an effect that can be done. Furthermore, in films of peptide resins such as gelatin, low molecular weight gelatin, grue, and casein, polymerization progresses due to plasma stimulation, which makes the film itself stronger and has side effects such as improved chemical resistance and reduced degree of thermal deformation. bring about.

The present invention will be explained in detail along with examples.

Example 1 FIG. 1 shows an embodiment of the present invention, in which a color filter 12 is printed on a transparent substrate 11 with pigment ink using an epoxy resin binder, and then a 1% Pressure of argon gas atmosphere containing oxygen gas 3×10 ^-3 Torr
A reverse spat ring was applied for 2 minutes at 2KW. After this, a 1200 Å film of a transparent electrode was formed by direct sputtering.

Adhesion was also sufficient in cellophane tape peeling tests and liquid crystal encapsulation.

Example 2 FIG. 2 shows one embodiment of the present invention, in which R (red), G (green), and B (blue) filters are coated on a transparent substrate 21 using gelatin by a known relief staining method. After forming a color filter 22 with a thickness of about 1.4 μm, an overcoat 24 of 0.3 μm was formed using the same gelatin. As in Example 1, reverse sputtering was performed in an argon gas atmosphere containing 1% oxygen gas. After this, an ITO film of 1200 Å was deposited by normal sputtering.

A mask pattern was formed using photoresist AZ1350 manufactured by Shipley, USA, and then a transparent electrode 23 was formed by etching with a 10% aqueous solution of hydrochloric acid.

No abnormality was observed in the overcoat 24 during etching, and no decolorization of the color filter 22 was observed.

The adhesion of the transparent electrode 23 was also sufficient in cellophane tape peeling tests and liquid crystal encapsulation.

In the above embodiments, the adhesion to transparent electrodes such as ITO was mainly explained, but the adhesion to other inorganic oxides such as SiO ₂ (silicon dioxide) is also improved.
Therefore, an inorganic oxide film such as SiO ₂ may be laminated in the gap or above the color filter as an intermediate layer, an alignment film, or a low reflection film. Further, even if a metal film for making electrical contact is added to the terminal portion and a metallization process is similarly applied for soldering or wire bonding, the object of the present invention will not be affected. Further, although the relief dyeing method was used in Example 2, a mask dyeing method may also be used.

<Effects of the Invention> According to the present invention, the adhesion of the transparent electrode has been improved, so that the peeling of the transparent electrode from the color filter, which has conventionally been observed, has been eliminated, and defects such as disconnection have been reduced.

It also showed sufficient heat resistance during heat treatment during the liquid crystal encapsulation process. Of course, the chemical resistance necessary for patterning the transparent electrode was also sufficient.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing an example of an electrode plate for a color display device obtained by the manufacturing method of the present invention, and FIG. 2 is a schematic sectional view showing an electrode plate for a color display device obtained by the manufacturing method of the present invention. FIG. 3 is a schematic cross-sectional view showing another embodiment of the plate, and FIGS. 3 and 4 are schematic cross-sectional views showing an example of a conventional electrode plate for a color display device. 11, 21, 31, 41...transparent substrate, 12,
22, 32, 42...color filter, 13,
23, 33, 43...transparent electrode, 24...overcoat.

Claims (1)

[Claims] 1. The color filter surface side of a transparent substrate having at least a color filter formed by coloring an organic resin with a colorant is sputtered at a ratio of oxygen gas to argon gas in the range of 0.1 to 15%. the pressure of
^10-4 Torr~ ^10-2 Torr, sputter voltage 0.5~5KV
Reverse sputtering treatment in an atmosphere containing oxygen,
A method for manufacturing an electrode plate for a color display device, which comprises subsequently forming a transparent electrode on the reverse sputtering treated surface. 2. The method for manufacturing an electrode plate for a color display device according to claim 1, wherein the reverse sputtering treated surface is the color filter surface itself. 3. The method for producing an electrode plate for a color display device according to claim 1, wherein the reverse sputtering treated surface is an overcoat surface on a color filter. 4. The method for manufacturing an electrode plate for a color display device according to claim 1, wherein the material of the color filter is one selected from gelatin, low molecular weight gelatin, grue, and casein. 5. The method for manufacturing an electrode plate for a color display device according to claim 1, wherein the material of the overcoat is one selected from gelatin, low molecular weight gelatin, grue, and casein.